Orbital Sciences turns to Atlas as it regroups from rocket explosion

Sidelined by a rocket explosion in October, Orbital Sciences will buy a United Launch Alliance Atlas 5 booster to launch its next International Space Station cargo ship for NASA, officials said on Tuesday.

Orbital’s fifth Antares rocket launch ended 15 seconds after liftoff from Wallops Island, Virginia, on Oct. 28 due to a problem with the booster’s refurbished Soviet-era engine. The accident claimed an unmanned Cygnus capsule loaded with more than 5,000 pounds (2,268 kg) of cargo for the space station, a $100 billion research laboratory that flies about 260 miles (418 km) above Earth.

Orbital announced last month it would speed up development of a previously planned Antares engine replacement and buy one or two rocket rides from another company to fulfill its contractual obligations to NASA.

Orbital said Tuesday it had selected United Launch Alliance’s Atlas 5 rocket to fly one Cygnus cargo ship in late 2015 and possibly a second freighter in 2016 if needed. Terms of the deal were not disclosed. United Launch Alliance is a joint venture of Lockheed Martin and Boeing. “In formulating its go-forward plans, the company’s primary objective is to fulfill its commitment to NASA for ISS cargo deliveries with high levels of safety and reliability and minimum disruption to schedules,” the company said in a statement.

Orbital is one of two firms hired by the U.S. space agency to fly cargo to the station following the retirement of the space shuttles in 2011. Orbital and privately owned Space Exploration Technologies each plan to deliver about 40,000 pounds of cargo under contracts worth $1.9 billion and $1.6 billion respectively.

Meanwhile, repairs to Antares launch pad and nearby facilities at the Mid-Atlantic Regional Spaceport in Virginia are expected to take about a year, with recertification targeted by the end of 2015, Orbital said.

Three Cygnus cargo ships will be launched from Virginia in 2016 on Orbital’s revamped Antares rocket. The company has not yet announced what engine will replace the troubled AJ-26, a Soviet-era motor that was purchased, refurbished and resold by GenCorp Inc's Aerojet Rocketdyne division. A faulty turbopump is believed to be the cause of the Oct. 28 Antares explosion.